in the case of dzhokhar tsarnaev even as we learn more about him and his life leading up to the bombing and what he is telling investigators, the question of why is intensely mysterious. if you spend some time on his twitter page as i did on the day it was first reported that he was a suspect, you'll find a teenager who mostly seems interested in stuff like weed, hip hop, girls, cars. it does not read like the twitter feed of someone who has completely devoted their life to a radical, violent cause but the twitter feed of a 19-year-old stoner. it reads like the twitter feed of a guy who transfers to a college because the parties are better there. even accounts from his friends who saw the surveillance photos released by the fbi thought you know that kind of looks like dzhokhar but somehow it was not him. it couldn't be dzhokhar, later telling "the boston globe" quote we made a joke like that could be dzhokhar but then we thought it just couldn't be him. dzhokhar? never. now, that profile emerging around the second suspect, the older brother tamerlan tsarnaev seems much less confounding